Somewhere out there!

3300 spam messages rejected on mail RCPT in the last six days. 550 per day.

That is 550 messages a day I don’t have to bother checking for false positives or manually deleting. I should have added SpamAssassian to Simscan much earlier.

You can see elsewhere on this site of how I installed Simscan with Qmail. Adding spam checking at the mail border with Simscan is was simply a matter of apt-getting SpamAssassian, recompiling Simscan by changing from

./configure --enable-workdir=/var/spool/simscan/ --enable-received=y

to

./configure --enable-workdir=/var/spool/simscan/ --enable-received=y --enable-attach --enable-spam --enable-spam-hits=5

and building a good copus of spam messages. Combined with a centralised bayes token file:

$ cat /etc/spamassassin/local.cf
#...
bayes_path        /var/spool/spamassassin/bayes
bayes_file_mode   0666

At the moment I’m added spam messages manually with sa-learn, but I expect I will setup a cron job in due course which checks an IMAP folder. Plus with this method the problem with false positives is much less, as senders of non-spam messages will received a definite non-delivery message. They are more likely to catch this than for me to notice them amongst 550 pieces of spam.